Controlling Your Emotions May Be Difficult Even Under Mild Stress

A team of neuroscientists from New York University (NYU) has found even mild stress can foil therapeutic measures to control emotions. The findings point to the limits of clinical techniques, while at the same time illuminating the barriers that must be overcome in addressing afflictions such as fear or anxiety.

“We have long suspected that stress can impair our ability to control our emotions, but this is the first study to document how even mild stress can undercut therapies designed to keep our emotions in check,” said Elizabeth Phelps, a professor in NYU’s Department of Psychology and Center for Neural Science. “In other words, what you learn in the clinic may not be as relevant in the real world when you’re stressed.”

The study findings were published in the Proceedings of the National Academy of Sciences (PNAS).

Therapists sometimes employ cognitive restructuring techniques which encourage patients to alter their thoughts or approach to a situation to change their emotional response when addressing the patients’ emotional maladies. These techniques might include focusing on the positive or non-threatening aspects of an event or stimulus that might normally produce fear.

The research team questioned whether these techniques hold up in real world situations when accompanied by the stress of everyday life. To answer this question, they designed a two-day experiment in which the study participants employed techniques like those used in clinics as a way to combat their fears.

On day one, the research team used a “fear conditioning” technique to create a fear among the participants. The subjects were shown pictures of snakes or spiders. Some of the pictures were accompanied by a mild shock to the wrist, while others were not. The researchers used physiological arousal and self-reporting to document that the participants had developed fear responses to the pictures that had been paired with shocks.

Next, in order to learn to diminish the fears brought on by the experiment, the participants were taught cognitive strategies akin to those prescribed by therapists and collectively titled cognitive-behavioral therapy (CBT).

On day two, the participants were separated into a “control” group and a “stress” group. The stress group participants’ hands were submerged in icy water for three minutes—a standard method for creating a mild stress response in psychological studies. The control group’s hands, in contrast, were submerged in mildly warm water. To determine if the participants in the stress group were indeed stressed, the researchers gauged the salivary cortisol levels of each participant. The human body produces salivary cortisol in response to stress. The control group showed no change, while the stress group showed a significant increase in cortisol.

The participants were given a short rest period, then they were shown the same pictures of snakes or spiders as on day one. This allowed the researchers to determine if stress undermined the utilization of the cognitive techniques taught the previous day.

The control group showed a diminished fear response to the images. This suggested to the researchers they were able to employ the cognitive training from the previous day. The stress group received identical cognitive training; however they were unable to use these cognitive techniques to reduce fear on the second day.

“The use of cognitive techniques to control fear has previously been shown to rely on regions of the prefrontal cortex that are known to be functionally impaired by mild stress,” Phelps observed. “These findings are consistent with the suggestion that the effect of mild stress on the prefrontal cortex may result in a diminished ability to use previously learned techniques to control fear.”

“Our results suggest that even mild stress, such as that encountered in daily life, may impair the ability to use cognitive techniques known to control fear and anxiety,” added Candace Raio, a doctoral student in NYU’s Department of Psychology. “However, with practice or after longer intervals of cognitive training, these strategies may become more habitual and less sensitive to the effects of stress.”